(1) Field of the Invention
The present invention belongs to a technical field of a graphics composition technique.
(2) Description of the Related Art
The graphics composition technique is a technique of compositing graphics such as subtitles or a GUI, to each frame of video which constructs a video stream, then displaying the result. As a technical trend of display device, displays that can display stereoscopic video as well as planar video are becoming popular. Various methods of stereoscopic viewing are adopted in the stereoscopic display devices, however, nearly all of the methods use the basic principle of displaying each of left eye and a right eye a different image to create stereoscopic effect, using binocular disparity.
In order to allow the viewers to view the stereoscopic video at the same frame rate as normal planar video, response performance twice as high as response performance needed for the normal planar video is necessary. This means, for example, that it is necessary to switch-among at least 120 frames per second in order to display video consisting of 60 frames per second.
Accordingly, the video stream to be displayed needs to be encoded at 120 frames per second. A stereoscopic effect may also be obtained without increasing the frame rate, by using a side-by-side method as described in a Non-Patent Document 1 or checker pattern method as described in Patent Document 2.
There is also, a technique known to generate stereoscopic images, that extracts information indicating the number of objects from a 2D video, then creating the number of layers corresponding to the number of objects so stereoscopic images can be generated by changing the depth of each of the layers as disclosed in a Patent Document 3.